The present invention relates to the support and movement of magnetic transducers, and more particularly, to a precision bearing for reciprocating a magnetic tape head.
Information is recorded and read from a moving magnetic storage medium with a transducer in the form of a magnetic head positioned adjacent the medium. Energization of the head and relative movement between the head and medium creates tracks of information on the surface of the medium during recording. These tracks can later be read using the same relative movement.
Data is typically recorded in tracks on a magnetic tape by moving the tape longitudinally past magnetic head, the latter being energized by a electric current representing the information desired to be recorded on the tape. The information is similarly read by moving the tape longitudinally past the magnetic head so that magnetic flux patterns on the tape create an electric current in coils associated with the magnetic head, the current being representative of the information being read.
The need for ever increasing amounts of magnetic media data storage has lead to efforts to obtain greater data density. One way of increasing the density of data stored in a given magnetic data storage medium is to increase the number of tracks and reduce the distance between adjacent tracks. As the spacing between adjacent tracks is reduced, the importance of precise alignment of the magnetic head with a selected track increases. Another way of increasing the density of data stored in a given magnetic storage medium is to increase the number of magnetic flux changes per unit length of data track.
By way of example, in a one-quarter inch cartridge tape drive system, there may be twelve data tracks each of which is 0.013 inch wide and has approximately 10,000 magnetic flux changes per inch. In systems of this type, the movement of the head transverse to the tape length must be very precise. Azimuth variations must be minimized to reduce read errors to acceptable levels when tapes are interchanged between drives.
An example of a magnetic tape drive having a precision bearing for supporting a read/write magnetic head for reciprocation across the width of the tape is disclosed in pending U.S. patent application Ser. No. 441,762 filed Nov. 15, 1982 entitled "Cartridge Tape Drive", assigned to Cipher Data Products, Inc., the assignee of the subject application. The disclosure of the aforementioned application is specifically incorporated herein by reference. The present invention is an improvement over the head bearing disclosed in application Ser. No. 441,762.